This is one of those things that definately could start heated arguments because both sides have valid points. Batch fire may not be optimal, but it certainly is capable of running an engine well. everything else in engine building is a compromise between cost, benefit, and performance so why would you not consider the reduced complexity and price of a batch fire system? there absolutely were OEM's that used a batch fire system, examples would be some of the Bosch Jetronic system as well as all of GM's TPI setups.

Jetronic is a mechanical continuous injection system...they added some electronics towards the end (I had one of those) but it was just an electronic injector that added more fuel to the plenum for cold start. Definitely not what is normally called batch and its not even efi.

GM TPI, I don't know enough to comment other than its a very old system that never made much hp....like 84? I know Porsche and ferrari stuck to the Bosch CIS (jetronic) until like '89 and on the ferraris at least that was sequential fuel with waste spark.

There is no valid argument to running an obsolete fuel system on purpose unless you're doing a restoration......

The most common batch injection system has to be the Ford EEC-IV control. It was on many millions of vehicles. Basically every gasoline fueled vehicle Ford made for 10-12 years had that control and central or port injection.

Yes, long obsolete, but the engines ran fine.

Of course I have no interest hacking that system. If I was going to hack something, it would be a newer GM PCM. Incredibly cheap to buy, but way over my head at this point.

I guess I should have been more specific and said Bosch "L-jetronic" and all of its varients that were used for about 20ish years. Ford EEC and TPI are other examples of OEM batch fire setups. So to say they were never used in OE applications is completely false. The main quality of a SFI system is emmissions, fuel economy, and idle/low speed operation smoothness, Those things generally arent the main priority of hotrodders. And yeah simple batch fire efi systems are "outdated" just like Carburetors, cam in block engines, distributers, halogen headlamps, and numerous other automotive systems that are still in widespread use today.

I'd venture to say that a ford 300 six project that is a first tume fuel injection projects is one of the best applications out there for the simplicity and low cost of a batch fire system.

I guess I should have been more specific and said Bosch "L-jetronic" and all of its varients that were used for about 20ish years. Ford EEC and TPI are other examples of OEM batch fire setups. So to say they were never used in OE applications is completely false.

I think, the D and L jetronic were 2 fuel ouptput systems...so on a 4 cylinder where they almost exclusively showed up they are a crude semi-sequential. TPI I never gave any thought to so you're probably correct.

The main reason you don't run sytems like that though is they don't make as much HP. As soon as you batch you lose control of the fuel pusle angle timing, any ability to adjuist the mixture in a specific cylinder and need to be very concerned about getting the fuel into the cylinder it's intended for (probably part of why TPI has the long runs)....and this all leads to lower hp and high fuel consumption.

Then on the street the idle and low power operation is poor and you have to pay for the higher fuel consumption...the idle quality is not a small difference. A couple times I've tuned engines in batch, bank, semi, full sequentail and its pretty obvious as you switch between them...no different than having a poorly tuned carb. I remember struggling to keep plugs clean...1 cylinder so lean it misfires while another it sooting up the plugs and no way to fix it other than redesign the intake and hope its better or replace the ECU.

15-20 years ago when a sequential systems cost significantly more to buy I could understand making the compromise.....but today when you really have to go out of your way to find a system that isn't sequential it just seems foolish, functional but foolish.

This thread is bringing back all kinds of bad memories. I had a haltech e6k installed on a v8 with wastespark...batch fuel (they called it multipoint).....it worked okish until the day I switched from an Eaton roots blower to a screen type. At low power the air wanted to go 1 way, at high power the other way, there was just no way to get it running right with batch injection.

Maybe an extreme case but it left such a bad taste in my mouth I vowed at the time that I'd never do a batchfire setup again....12 years later and I still haven't.

I guess I should have been more specific and said Bosch "L-jetronic" and all of its varients that were used for about 20ish years. Ford EEC and TPI are other examples of OEM batch fire setups. So to say they were never used in OE applications is completely false.

I think, the D and L jetronic were 2 fuel ouptput systems...so on a 4 cylinder where they almost exclusively showed up they are a crude semi-sequential. TPI I never gave any thought to so you're probably correct.

The main reason you don't run sytems like that though is they don't make as much HP. As soon as you batch you lose control of the fuel pusle angle timing, any ability to adjuist the mixture in a specific cylinder and need to be very concerned about getting the fuel into the cylinder it's intended for (probably part of why TPI has the long runs)....and this all leads to lower hp and high fuel consumption.

Then on the street the idle and low power operation is poor and you have to pay for the higher fuel consumption...the idle quality is not a small difference. A couple times I've tuned engines in batch, bank, semi, full sequentail and its pretty obvious as you switch between them...no different than having a poorly tuned carb. I remember struggling to keep plugs clean...1 cylinder so lean it misfires while another it sooting up the plugs and no way to fix it other than redesign the intake and hope its better or replace the ECU.

15-20 years ago when a sequential systems cost significantly more to buy I could understand making the compromise.....but today when you really have to go out of your way to find a system that isn't sequential it just seems foolish, functional but foolish.

I could not agree more
There are several standalones available for not much more money than the megasquirt
And some of the most important factors for a street driven engine is for it to run smooth from idle through midrange
It is (like you said) often day and night difference running batch and sequential
Running waste spark might be ok,but why do it when there are systems who allow you to run individual
A system like i mentioned is also much easier to install since it has a finished wire loom with labeled wires and several options for various input/outputs for most anything,and it is also MUCH easier to tune than a MS
It (as mentioned before) also comes with a wideband and a map sensor and a quite long list of injectors where all their data is allready stored in the software,same goes for different intake temp and water temp sensors,different trigger sensors,even different speed sensors
Spending some time on making a good crank/cam trigger installation and using injectors of decent quality is also crucial
Batch injection is not much better than a carb set-up in my opinion

Waste spark is fine but batch or semi-sequential fuel kind of sucks and that's what you'd be stuck with if you choose a 4cyl ecu like a microsquirt.

There seems to be proponents both of sequential and batch. (And “enthusiastic discussions” about their merits)

The only proponents of batch are the people who buggered up there fuel rail sizing so badly it won't run any other way and they don't want to fix it.

The only proponents of semi-sequential are people too cheap to buy a proper ecu or too lazy to install the proper sensors required for full sequential.

Seriously....those systems both fall in "the better than nothing" bucket. I don't think there has ever been an oem batch-fire anything and semi-sequential came and went pretty quick...because it doesn't work all that well. The higher end oems suck to mechanical continuous injection until sequential options were available, that should tell you something. The difference is only a couple hundred $ between and ecu that does everything right and the cheapest option you can possibly find to make work.....the ecu is the brain of the engine and controls how the entire project acts, why on earth would you pick one of the most critical components to skimp on? Seems like penny wise and pound foolish to me but it is your money and your project so I hope all turns out to your liking.

LT1 ecm cars, 92-97 GM V-8s all had batch fire to one degree or another. Some like the early years were batch only, the rest would do sequential at idle and do a blended mode up to 3000rpm before becoming batch fire.

Whats with the dislike of Megasquirt? I wonder how many people that are commenting here have actually tried a new Megasquirt 3 system.

I have a Megasquirt 3 (engine control) and a Microsquirt (transmission control) hooked up by CANBUS to drive my automatic transmission and turbo V8 car. A Microsquirt can run a V8 engine in batch mode. The downside to running a Micro is that you only have one 35 pin connector and you run out of room very quickly on your inputs and outputs. Also as mentioned earlier you won't be able to use a IAC 4 wire GM stepper motor. Instead you'll have to do a little messing around with spark and fuel to get it to idle.... or buy the IAC add on.

When I bought my MS3 a few years back I got an ECU and harness, 80lb Siemens Deka Injectors, TCU and harness, all for the price of what a bare Holley Dominator box cost.

The MS3 box has two 35 pin connectors so there is a ton of room for sensors and inputs/outputs.

I still haven't used fan control, Variable Valve Timing, Fuel Table Switch, Nitrous, Turbo Anti Lag, Launch Control, Transbrake or a few of the sensor inputs.

So many options to mess with, when I ran it on the engine dyno it was pretty amazing to be able to just on the fly change fueling and timing without having to shut off the engine and make adjustments to a distributor or carb. I got a whole lot more pulls on the dyno that I normally do with a carb engine for the same amount of time on the dyno.

There seems to be proponents both of sequential and batch. (And “enthusiastic discussions” about their merits)

The only proponents of batch are the people who buggered up there fuel rail sizing so badly it won't run any other way and they don't want to fix it.

The only proponents of semi-sequential are people too cheap to buy a proper ecu or too lazy to install the proper sensors required for full sequential.

Seriously....those systems both fall in "the better than nothing" bucket. I don't think there has ever been an oem batch-fire anything and semi-sequential came and went pretty quick...because it doesn't work all that well. The higher end oems suck to mechanical continuous injection until sequential options were available, that should tell you something. The difference is only a couple hundred $ between and ecu that does everything right and the cheapest option you can possibly find to make work.....the ecu is the brain of the engine and controls how the entire project acts, why on earth would you pick one of the most critical components to skimp on? Seems like penny wise and pound foolish to me but it is your money and your project so I hope all turns out to your liking.

LT1 ecm cars, 92-97 GM V-8s all had batch fire to one degree or another. Some like the early years were batch only, the rest would do sequential at idle and do a blended mode up to 3000rpm before becoming batch fire.

Whats with the dislike of Megasquirt? I wonder how many people that are commenting here have actually tried a new Megasquirt 3 system.

I have a Megasquirt 3 (engine control) and a Microsquirt (transmission control) hooked up by CANBUS to drive my automatic transmission and turbo V8 car. A Microsquirt can run a V8 engine in batch mode. The downside to running a Micro is that you only have one 35 pin connector and you run out of room very quickly on your inputs and outputs. Also as mentioned earlier you won't be able to use a IAC 4 wire GM stepper motor. Instead you'll have to do a little messing around with spark and fuel to get it to idle.... or buy the IAC add on.

When I bought my MS3 a few years back I got an ECU and harness, 80lb Siemens Deka Injectors, TCU and harness, all for the price of what a bare Holley Dominator box cost.

The MS3 box has two 35 pin connectors so there is a ton of room for sensors and inputs/outputs.

I still haven't used fan control, Variable Valve Timing, Fuel Table Switch, Nitrous, Turbo Anti Lag, Launch Control, Transbrake or a few of the sensor inputs.

So many options to mess with, when I ran it on the engine dyno it was pretty amazing to be able to just on the fly change fueling and timing without having to shut off the engine and make adjustments to a distributor or carb. I got a whole lot more pulls on the dyno that I normally do with a carb engine for the same amount of time on the dyno.

I have not tried the MS3 only some older MS,which was utter crap in my opinion
Have you tried some other standalones other than MS3?

I have not tried the MS3 only some older MS,which was utter crap in my opinion
Have you tried some other standalones other than MS3?

I did quite a bunch of research before going MS3, I looked at close to a dozen different units before deciding. Haltech, Holley Dominator, FAST XFI, MoTeC, Big Stuff 3, even got to look at one of the first FuelTech boxes that was on Larson's truck. After adding up the options needed for me to run a electronically controlled transmission, there wasn't a whole lot of viable options left. Lots of ECUs come and go, BS3 and FAST used to be king, but now you don't see them much anymore. Everyone seems to have gone to Holley/Motec/FuelTech.

This is a street vehicle I don't want to be driving around in a manual valve body T400 or a Powerglide.

My experience with EFI before going MS3 was with programming stock GM computers LT1 and LS1 24x. Some of the stock LS computers are so good that you can avoid going aftermarket ECU, P59 computers with the IAC chip are the top.

As it sits today I could have modified a stock ECU to handle 3Bar Map, 210lb Injectors, controlled a 4l80e transmission, and kept my dash. Either it wasn't known or I didn't find information on how to do it until a year or so ago. I bought the MS3 nearly 3 years ago and it has worked great.

A modern stock ecu is far superior to just about any standalone,
However a modern standalone is easier to tune than a stock ecu,thats the whole idea behind a standalone,for a normal "John Doe" to be able to make his own tune,with mixed results there also ofcourse but that depends on experience and knowledge

Motec has always been a top brand,but in earlier years it was just too expensive for the average hotrodder
The last 4-5 years the pricing has come down alot,they even released some simpler lower cost versions but those are not available anymore afaik

I have tried MS1,Autronic,Motec and Maxxecu
And i have to say the Maxxecu is most value for the money

I have a turbo ls running on a micro squirt. Junk yard Engine got an oil change ,spark plugs , turbo and microsquirt. Runs mid 11''s on 8 psi and drives nice in a Malibu wagon .winter cold starts still need tuned better. I also own a 1992 firebird with a very mild 383 no weight reduction that runs mid 12''s @109 on the factory batch fire ecu. I changed to 30 lb/hr injectors in the firebird and I had no problem editing the factory fuel tables and timing tables . That vehicle has excellent driving manners and decent fuel economy.

Sequential stuff is better but batch stuff is like a carb setup with data logging built in. It works pretty good.

If it's primarily a street car, i'd just go straight for the MS3X and sequentially fire your injectors and coils. In the upper rev range, the PW is that high it's pretty will batch firing, but the sequential firing really does make something seem "wild" on paper function really nicely. One thing to be aware of is that if you go microsquirt with batch fuel - wasted ignition you'll need to use a 2-wire PWM idle valve, you can't use a 4-wire GM stepper. I've run my MS3X on my 400 Poncho for MANY years now, the only part of the car that's ever failed was an MSD ignition coil before I went 8xLS1 coils. The ECU itself has been super reliable for a v3.0 DIY solder together job at home but nowadays i'd just go a 3.57 SMD version or PRO. Be very meticulous with the wiring (as with any EFI system really) and keep it neat/clean, pay extra attention to the grounds! Megasquirt has very good information around grounding strategies as if you get it wrong it can send you down a rabbit hole - again this applies to any ECU.